Sounds like my youngest son. I myself was getting worried around 8 months when he didn't roll, sit up, etc and refused all solid food. Think now it was because he was just so dang FAT! It only took another month and a half and he was walking. Still didn't eat food untill nearly a year no matter what or how I tried. Now at 6 he is the smartest most active child I have ever known. He still doesn't eat a whole lot though.